Room pressurization is important for preventing unwanted airflow in certain environments, such as negative static pressure in chemical and biological facilities, or positive static pressure in food and drug processing operations. A room can be maintained at a negative static pressure with respect to an adjacent area by airflow tracking, which always removes more air from the room than is supplied to the room. This creates a slight vacuum condition within the room. Similarly, a room can be maintained at a positive static pressure with respect to an adjacent area by airflow leading, which always supplies more air to the room than is removed from the room. This creates a slight pressurized condition within the room.
Pressure dependent environments that use 100% outside air supply typically consume a substantial amount of energy to operate because outside air is so expensive to condition. Part of the problem lies with limitations in the terminal box controller configuration. When static values, such as a differential pressure set point and air change per hour set point, are used for terminal box controller configuration, the room will typically have high energy usage, compliance related issues, or both when there is an event or unfavorable change in the heating, ventilating and air conditioning (HVAC) system.
As a result, there is a need for room pressurization control systems and methods that adaptively optimize the air change per hour set point to maximize energy savings while operating within the environmental requirements of the room.